If you remember only one thing I've said, remember that an idea is a feat of association, and the height of it is a good metaphor. If you have never made a good metaphor, then you don't know what it's all about.
As one who sees in dreams and wakes to find the emotional impression of his vision still powerful while its parts fade from his mind - Just such am I, having lost nearly all the vision itself, while in my heart I feel the sweetness of it yet distill and fall.